This invention is in the field of devices for producing dynamic infrared images. Such devices are used to test various night vision systems. When testing night vision systems, a number of stimuli are employed: these range from wholly synthetic images, such as bar targets and other geometrical patterns, to actual live targets in natural scenes. The geometric patterns are needed to perform repeatable objective tests of such parameters as modulation transfer function, minimum resolvable temperature, resolution, etc. However, experience has shown that the complexities of the natural environment are such that they are not modeled adequately by synthetic images to provide a comprehensive evaluation of a system; consequently, knowledgeable testers resort to viewing natural scenes before judging a given system as acceptable. The advent of more advanced systems has exacerbated the problem. These are the automatic systems, which include automatic control functions such as auto gain, auto brightness, auto focus, auto level and auto responsivity controls, automatic target trackers, automatic target cuers, and automatic target recognizers, as well as combinations of any and all of the above functions. Testing of these systems invariably demands the use of images of natural terrain and targets because of the almost unsurmountable difficulty involved in producing validated synthetic images. The night vision testing community has recognized that there is a need for repeatable imagery of natural scenes. That is, imagery that has been recorded, and can be reproduced repeatedly in a consistent fashion that would retain the same radiometric attributes no matter how many times it were reproduced. This can eliminate some of the variables encountered in field trials, where there are day-by-day, hour-by-hour and sometimes minute-by-minute changes in the scene conditions. This makes it difficult to compare different systems or even the same system employing different parameters or different algorithms. It is highly desireable to test entire systems' performance, as there are sometimes unexpected and often subtle interactions between the individual components. This is done by observing and measuring the output while inputting an image. Such a test is reasonably easy to accomplish with the image intensifier class of devices, as they operate in the visible and near infrared regions of the spectrum, and thus can use slightly modified film projectors, and other readily obtainable image sources. In addition, there are available CRT's with phosphors having significant output in the near-IR. Producing equivalent images in the longer wavelength portion of the infra-red spectrum has been far more difficult, and less work has been done in the past on this, because of its very limited application. As described above, the simplest form of test target used for evaluating an infrared device has been the geometrical targets. These are typically stencil-like reticles which are cut out of a thin sheet of metal. A blackbody source is placed behind the reticle, and because the surface of the reticle is of a different temperature from the source, a condition of thermal contrast then exists. These reticle targets are used for objective tests of specific parameters, but are of very limited usefulness for evaluating complex automatic systems. One of the methods which have been used to generate repeatable images of natural scenes is: printing half-tone images on sheet- metal substrates and affixing these to a heated metal panel. Heat from the panel is conducted through the interface to the substrate. Differences in emissivity of the bare metal substrate and of the halftone image inscribed on it cause apparent delta T's. A more advanced approach is the "Bly Cell". (U.S. Pat. Nos. 4,178,514 of Dec. 11, 1979, and 4,299,864 of Nov. 10, 1981). In this approach an extremely thin membrane is mounted in an evacuated cell with a window parallel to the membrane on each side. The membrane is coated with a material such as gold black, which absorbs photons at one wavelength and re-radiates them at another wavelength. In this case, the wavelength of the input signal is in the visible to near-infrared portion of the spectrum. The output is wideband, approximating a blackbody emitter. The Bly Cell is used as follows: a visible image is projected, using an intense light source, onto the membrane. The recording medium for the image may be either a slide transparency or motion picture film. The output is then observed by an infrared device under test. The disadvantages of the heated panel approach are several: the substrates are costly to make and require considerable manual handling; the range of apparent delta T is limited; only static images are practical; reflections from objects in the simulator viewing chamber cause artifacts in the image and; the substrates must be manually placed on the panel. While the Bly Cell is an improvement over reticles and heated panels, it still has several disadvantages: its power sensitivity is low, making it unsuitable for use with a cathode ray tube output image; it is difficult to construct, and is therefore expensive; apparent delta T's are limited to a few degrees C. Earlier, when most advanced night vision imagery was being collected from image intenifier devices, the recording medium was primarily either still or motion picture film. However, for many reasons, this has been supplanted almost entirely by video tape. Video tape has many advantages, including ease of operation, consistency of performance, ease of interface, and the ability to be reviewed immediately after recording, without processing. The advent of the digital scan converter and of high bit rate digital recording extends this capability even further by permitting the recording of extremely wide dynamic range, high resolution, and high quality imagery. The instant invention overcomes the disadvantages of the prior art devices, particularly since it is capable of using to advantage video recorded data.